Giant cell arteritis-related aortitis with positive or negative temporal artery biopsy: a French multicentre study

{Objective: To compare the clinical presentation and outcome of giant cell arteritis (GCA)-related aortitis according to the results of temporal artery biopsy (TAB). Method: Patients with GCA-related aortitis diagnosed between 2000 and 2017, who underwent TAB, were retrospectively included from a French multicentre database. They all met at least three American College of Rheumatology criteria for the diagnosis of GCA. Aortitis was defined by aortic wall thickening > 2 mm on computed tomography scan and/or an aortic aneurysm, associated with an inflammatory syndrome. Patients were divided into two groups [positive and negative TAB (TAB+, TAB-)], which were compared regarding aortic imaging characteristics and aortic events, at aortitis diagnosis and during follow-up. Results: We included 56 patients with TAB+ (70%) and 24 with TAB- (30%). At aortitis diagnosis, patients with TAB- were significantly younger than those with TAB+ (67.7 +/- 9 vs 72.3 +/- 7 years